The invention relates to a control device arrangement according to claim 1. Such a device is used, for example, for controlling functions of a working machine, particularly a forestry machine.
Lever-shaped devices are widely used for controlling functions of current working machines. In the following, they are called control devices. By moving such a control device, some of the main functions of a working machine, such as movements of a working boom of a forestry machine, are thus controlled. In addition to the control device, other important functions of the working machine, such as controlling telescopic, out- and inwards directed movements of a boom of a forestry machine, are often connected to push buttons at the handle of the control device. Two kinds of control devices are used in forestry machines. The more common control device is long, has a large range of movement and can also be compared with a joystick used in computer games and planes. Such a control device is moved by using the entire hand and forearm. However, this has often been noticed to cause too much tension in shoulders, wherefore xe2x80x98minileversxe2x80x99 have become more common. The range of movement of these considerably small control devices is so small that the control devices can be used by moving fingers and the wrist, whereas the arm of the working machine driver rests mainly against the armrest of the seat. Thus, the structure of the control device must be both small and light.
In the most advanced working machines, such as chippers, the controls performed by the handle of the control device and the operating switches at the handle are not sufficient for carrying out all functions and choices of the machine. In addition, also an independent small keyboard is required, which is close to the control device. Usually such a keyboard is positioned so that it can be used by fingertips of the hand moving the control device.
Since the controlling of a working machine demands great accuracy, much attention should be paid to the ergonomics of such control means. Although the range of movement of the control device is made as small as possible, the problem which arises when using a keyboard in connection with such a control device is how the fingers of the driver controlling the working machine are made to reach to all keys at all operating positions of the control device. One common way to solve the problem caused by the structure of long control devices as control means is that the keyboard is fixed to the same armrest of the seat in the working machine as the control device itself. Thereby it is almost impossible to use all keys at all extreme positions of the control range efficiently. Another commonly used solution is to fix the keyboard to the handle of the control device. This requires, however, that a relatively heavy control device with a large range of movement is used, which causes that it is cumbersome to use the handle and that the handle is heavy. Therefore, when a small control device is used, it has to be made small and light. However, it has not been possible to arrange keys at the handle in the similar manner as in long control devices.
It is an object of the present invention to substantially reduce prior art problems and provide a new type of solution which facilitates the use of control means considerably. The object is achieved such that the arrangement has the characteristic features defined in the claims according to the present invention. More specifically, the arrangement according to the present invention is chiefly characterized by what is said in the characterizing part of claim 1.
The arrangement according to a preferred embodiment of the invention, whereby a supporting plate supporting the keyboard is arranged in connection with the handle, enables the movements of the control device and those of the keyboard in connection with it to be connected to each other such that when the control device is moved, this does not considerably hinder the user from reaching and pressing the keys. The supporting plate attached to the handle of the control device follows the movements of the handle easily. On the other hand, the supporting plate according to the invention forms a structure which surrounds the handle from all sides, and thus the weight of the supporting plate and keyboard does not disturb the balance of the handle. Consequently, springs that control movements of the handle need not be made particularly stiff, which improves the ergonomics and controllability of the control device.
The keys that are on the supporting plate in connection with the handle of the control device can be easily reached by fingers. The supporting plate can also be constructed such that it extends past the armrest supporting the control device and covers up all the mechanical parts of the control device.
The preferred embodiments of the invention are disclosed in the dependent claims.
Thus, in a specific embodiment of the invention the structure of current small xe2x80x98minileversxe2x80x99 is taken into account such that the supporting plate is not fixed to the handle at all, but it is arranged at the frame section of the control device in a sliding manner. Thus, the handle pushes the supporting plate ahead of it along bearing surfaces, and the stress applied to the handle remains as weak as possible.
On the other hand, the structure can be understood as an integration of the supporting plate and the handle, which is simple to manufacture and operates reliably.